The Ricoh Caplio Pro G3 has the ability to add custom fields to the APP5
"RMETA" segment of JPEG images. While only a few observed tags have been
defined below, ExifTool will extract any information found here.

Lens units available for the GXR, used by the Ricoh Composite LensID tag. Note
that unlike lenses for all other makes of cameras, the focal lengths in these
model names have already been scaled to include the 35mm crop factor.